Advertisements
Advertisements
Question
A 12 pF capacitor is connected to a 50 V battery. How much electrostatic energy is stored in the capacitor? If another capacitor of 6 pF is connected in series with it with the same battery connected across the combination, find the charge stored and potential difference across each capacitor.
Advertisements
Solution
`E=1/2CV^2`
`E=1/2×12×10^-12×(50)^2`
`E=1.5×10^-8 J`
`C_(eqv)=(C_1C_2)/(C_1+C_2)`
`=(12×6)/(12+6)`
`=72/18`
`=4×10^-12 F`
`Q=C_(eqv)V`
`=4×10^-12×50`
`=200×10^-12 C`
Charge stored in both capacitor is `200×10^-12 C`.
Voltage across 12 pF capacitor is `=Q/C= (200×10^-12)/(12×10^-12)=200/12=16.67 V`
Voltage across 12 pF capacitor is`=Q/C= (200×10^-12)/(6×10^-12)=200/6=33.33 V`
APPEARS IN
RELATED QUESTIONS
A spherical conducting shell of inner radius r1 and outer radius r2 has a charge Q.
(a) A charge q is placed at the centre of the shell. What is the surface charge density on the inner and outer surfaces of the shell?
(b) Is the electric field inside a cavity (with no charge) zero, even if the shell is not spherical, but has any irregular shape? Explain.
Define electrostatic potential at a point. Write its S.I. unit. Three-point charges q1, q2 and q3 are kept respectively at points A, B, and C as shown in the figure, Derive the expression for the electrostatic potential energy of the system.
A point charge is placed at the centre of a hollow conducting sphere of internal radius ‘r’ and outer radius ‘2r’. The ratio of the surface charge density of the inner surface to that of the outer surface will be ______.
If R is the radius of a spherical conductor, Vm the dielectric strength, then the maximum electric-field magnitude to which it can be raised is ______.
The electrostatic potential on the surface of a charged conducting sphere is 100V. Two statements are made in this regard S1 at any point inside the sphere, electric intensity is zero. S2 at any point inside the sphere, the electrostatic potential is 100 V. Which of the following is a correct statement?
Which of the following statement is true?
A test charge q is made to move in the electric field of a point charge Q along two different closed paths (Figure). First path has sections along and perpendicular to lines of electric field. Second path is a rectangular loop of the same area as the first loop. How does the work done compare in the two cases?
Consider a finite insulated, uncharged conductor placed near a finite positively charged conductor. The uncharged body must have a potential:
